Payment transaction systems that use a mobile data terminal to handle credit/debit card transactions for a merchant are known. Typically, the merchant's data terminal is a mobile smartphone, tablet computer or portable computing device with cellular data communication capabilities, such as General Packet Radio Service (GPRS), Enhanced Data rates for GSM Evolution (EDGE) or 3G (3rd generation mobile telecommunications technology), and capable of running a payment application. A payment card reader is also typically provided as a peripheral device in communication with the data terminal. The payment application preferably provides accounting functions for the merchant, such as calculating a total bill, printing receipts, providing summaries of transactions, etc. and can communicate electronically with a transaction processing back-end server to process and settle the transactions.
Examples of such known systems are described in GB No. 2427059 (Bristol Office Machines), EP No. 0741884 (mCom Solutions) and EP No. 1240631 (Swisscom Mobile AG).
As such card payment systems become more prevalent, there is a need for improved systems and techniques to provide greater security for transactions and reduce the risk of fraudulent use.